textproduct: Albany

WHAT HAS CHANGED

Convective outlook is relatively unchanged at this time, with marginal to slight risk across much of the area on Tuesday and marginal risk for southern areas on Wednesday. Main threat looks to be damaging winds.

Hot and humid weather will peak on Tuesday. Heat Risk slightly increased, with some areas in the major category. Some parts of the mid Hudson Valley, Capital Region and NW CT may see heat index values briefly approach 95 during the mid to late afternoon hours on Tuesday.

KEY MESSAGES

1) Well-above normal temperatures will continue through the middle of the week. With Heat Risk values in the moderate to locally major category, there is an increased risk for heat- related illnesses, especially on Tuesday.

2) Ahead of a cold front, scattered thunderstorms are expected on Tuesday afternoon and evening, especially for northern areas. Additional storms are possible on Wednesday afternoon, mainly for southern parts of the area. There is marginal to slight risk for storms to be severe, with damaging winds being the main threat.

3) A return to more seasonable temps is expected late this week with the next chance for widespread rain being next weekend.

DISCUSSION

KEY MESSAGE 1...

On Tuesday, southwest flow aloft will continue to allow for 850 hpa to rise to +15 to +19 C across the region. The low-level flow out of the south to southwest will keep the warm and increasingly muggy air mass in place as well. Although dewpoints will initially be in the mid 60s, model soundings shows excellent mixing to about 775-800 mb, which may help lower dewpoints somewhat during the mid to late afternoon hours. Still, a partly to mostly sunny sky and a southwest wind downsloping off the Catskills will allow for a very warm day for mid May, with high temperatures reaching close to record values for the date, with highs in the lower to middle 90s. Heat index values will likely be similar to actual air temps in the mid to late afternoon hours due to the mixing, so the humidity won't be quite mid summer levels. Still, anyone spending time outdoors on Tuesday will need to practice heat safety, especially since it's early in the season and many people aren't used to this extreme heat just yet this year. WPC Heat Risk is still widespread in the moderate (level 2 of 4), although some areas of major (level 3 of 4) are starting to appear for southern areas. It's borderline Heat Advisory criteria, but based on collaboration with neighboring offices, won't go with one just yet due to heat index values mainly below 95 degrees, but it's rather close.

With a cold front coming through, most areas will see cooler temps and a drier air mass starting to arrive on Wednesday, although far southern areas will remain ahead of the front for most of the day. A moderate heat risk is still expected for the mid Hudson Valley with highs still approaching 90 by the afternoon hours before the front arrives late in the day. Heat- related illnesses will still be a concern for southern areas on Wednesday.

KEY MESSAGE 2...

There will be a threat for strong to severe thunderstorms on Tuesday, mainly for northern areas. Our area will on the northern edge of the upper level ridging centered over the eastern seaboard, while an upper level disturbance moves across the Upper Great Lakes. As this disturbance approaches, 0-6 km bulk shear will be increasing through the day, with 30-40 kts across northern areas by the afternoon hours. Although mid level lapse rates will be rather poor to start, they may start to increase by late in the day as the upper level height falls get a little closer to the area. Surface-based instability will be sufficient for storms due to the warm and somewhat humid air mass in place, with model values showing about 500-1000 J/kg.

CAMs suggest some scattered activity may spread across the Adirondacks and Lake George Saratoga Region beginning in the early to mid afternoon hours and it will spread eastward or southeast for late in the day. Some activity will be possible for the I-90/Capital Region corridor by later in the day as well. 2-5 km updraft helicity isn't overly impressive and CAMs haven't been suggesting much organization, but there should be enough overlap of shear and instability to suggest some storms could be strong to severe. The main threat would be damaging wind gusts with any storm on Tuesday.

Some additional storms are expected on Wednesday just along or ahead of the cold front for the afternoon hours. Models suggests there will once again be about 30-40 kts of shear with SBCAPE in the 500-1500 J/kg range. This would primarily impact the mid Hudson Valley, Taconics and western New England. Once again, damaging wind gusts would be the main threats. SPC has a marginal risk for Wednesday and this looks reasonable at this time. Any threat for storms will decrease as the boundary drops north to south across the region, with the front exiting our area by the early evening hours.

KEY MESSAGE 3...

Behind the front, cooler and drier air will arrive for Thursday into the late week. Daytime temps will only be in the 60s for valley areas for Thursday and Friday. Overnight lows will generally be in the 40s, with some mid to upper 30s possible for the highest terrain of the Adirondacks and southern Vermont.

A widespread rainfall is expected over the holiday weekend, although exact QPF, timing and duration of precip is still in question. Models have suggested this could be a slow-moving system, although haven't been consistent on this just yet. With steady rainfall and plenty of clouds, temps could be held down below normal during the rainfall, which may impact holiday weekend plans.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

Through 00z Wednesday...Flying conditions are VFR at all terminals as of 7:20 PM EDT, with VFR conditions expected to prevail through most if not all of the TAF period. Just a few passing mid and high clouds expected tonight into tomorrow, with additional daytime cumulus clouds developing by late tomorrow morning with bases 6000- 8000 ft. An approaching upper disturbance may lead to isolated to scattered showers and thunderstorms tomorrow afternoon. Low confidence on if any showers/storms will occur and if so how widespread they will be, but have introduced prob30s at ALB/GFL/PSF where confidence is highest to at least mention the possibility. MVFR to possibly IFR vsbys within any heavier showers/storms, but otherwise VFR conditions persist through at least 00z Wednesday.

Winds will be from the S/SE at 5-10 kt tonight, but with a W/SW low- level jet at 35-40 kt moving overhead have continued mention of LLWS from around midnight tonight through 12z tomorrow. Winds tomorrow morning shift to the S/SW at 5-10 kt, and then by late morning to the W/SW at 10-15 kt with gusts of 20-25 kt through the afternoon and early evening. Locally stronger gusts also possibly with any thunderstorms tomorrow afternoon.

Outlook...

Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Moderate Operational Impact. Breezy. Chance of SHRA...TSRA. Wednesday Night: Low Operational Impact. Breezy. NO SIG WX. Thursday: No Operational Impact. NO SIG WX. Thursday Night: No Operational Impact. NO SIG WX. Friday: No Operational Impact. NO SIG WX. Friday Night: Moderate Operational Impact. Chance of SHRA. Saturday: High Operational Impact. Likely SHRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...Air Quality Alert until 11 PM EDT this evening for CTZ001-013. NY...Air Quality Alert until 11 PM EDT this evening for NYZ063>066. MA...None. VT...None.